1. Field of the Invention
This invention relates to trash enclosures and more particularly to trash enclosures having an automatic lid.
2. Previous Art
Trash enclosures may hold trash of all types. Trash may include household garbage, restaurant garbage, medical waste, chemical waste, and other industrial waste. Enclosures may partially or fully enclose trash depending on the type of trash to be enclosed. Trash enclosures often have lids which open to receive trash and close to contain odor, hide trash from view and prevent the trash from contaminating areas beyond the enclosure.
Lids are often opened by hand. Hand opened lids have several problems. In some cases, contact between a hand and the lid may spread contamination. Additionally, sometimes a free hand may not be available to open the lid.
Medical workers and food handlers, for example, may not wish to contact trash containers to avoid biological contamination. Similarly, chemical workers may not wish to contact a container such as a trash enclosure which holds chemical contaminants. Contact with any potentially contaminated container is undesirable.
In fast food restaurants, food is often served on trays. Upon finishing a meal, the trays are carried to a trash container where the trash is dumped and the tray deposited. Fast food wrappers and other waste may fly off of the tray when being dumped into the container. Two hands may be necessary to carry and dump such a tray without spilling the waste. It can be appreciated that a free hand is not always available for opening the lid and waste may spill as a result. In particular, trash may spill if the lid is not properly held open because the lid may push the trash off of the tray. This situation may be observed at many fast food restaurants which have hand operated trash enclosure lids. Such spills are sought to be avoided.
In order to facilitate insertion of trash into a trash enclosure, automatically operable lids have been developed. Such automatically operable lids may be fitted with a sensor system which automatically opens the lid upon demand. Ideally, such enclosures will eliminate the need for pushing the lid open by hand. An example an enclosure having a sensor is described in U.S. Pat. No. 4,981,275 to Sheu, the disclosure of which is incorporated herein by reference.
The Sheu invention relies upon a sensor mounted on the face of the trash enclosure. The sensor detects objects in front of the enclosure and causes the lid to open in response to detection of an object. Accordingly, a passerby may inadvertently activate the sensor and cause the lid to open. Inadvertent opening of the lid may unnecessarily release odor and contaminants from the trash enclosure. Accordingly the lid should not be inadvertently opened.
Photoelectric eyes may rely on visible light. When visible light is relied upon, the sun and other light sources could interfere with the operation of the sensor. What is desired is an enclosure having a sensor which does not mistakenly activate due to interference with visible light sources, the presence of passers by, or other causes.